#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>

char *menu[] = {
    "a -add new record",
    "d -delete record",
    "q -quit",
    NULL,
};

int getchoice(char *greet, char *choices[],FILE *in,FILE *out);

int main(){
    int choice = 0;
    FILE *input;
    FILE *output;

    if (!isatty(fileno(stdout))){
        fprintf(stderr,"You are not a terminal,OK.\n");
    }

    input = fopen("/dev/tty","r");
    output = fopen("/dev/tty","w");
    if (!input || !output){
        fprintf(stderr,"Unable to open /dev/tty\n");
        exit(1);
    }
    do{
        choice = getchoice("Please select an action",menu,input,output);
        printf("You have chosen:%c\n",choice); // 程序其他输出被重定向到文件file中
    } while (choice != 'q');
    exit(0);
}

// 通过向getchoice函数传递参数的方法来加强对输出的控制
int getchoice(char *greet, char *choices[],FILE *in, FILE *out){
    int chosen = 0;
    int selected;
    char **option;

    do{
        fprintf(out,"Choice:%s\n",greet);
        option = choices;
        while (*option){
            fprintf(out,"%s\n",*option);
            option++;
        }
        do{
            selected = fgetc(in);
        } while (selected == '\n');
        option = choices;
        while (*option){
            if (selected == *option[0]){
                chosen = 1;
                break;
            }
            option++;
        }
        if (!chosen){
            fprintf(out,"Incorrect choice,select again\n");
        }
    }while (!chosen);
    return selected;
}